Mill-Turn Components
Parts completed in one mill-turn cycle - turned, milled and drilled without refixturing.
Parts that would normally need three operations, done in one. Mill-turn suits anything with turned features plus off-axis holes or flats, where refixturing is where the position error comes from.
How we make it: Precision CNC machining service →
3–5 weeks
25 pieces
ISO 9001:2015 · IATF 16949
Technical Specifications
| Parameter | Value | Unit |
|---|---|---|
| Diameter tolerance | ±0.005 | mm |
| Cross-hole position | ±0.02 | mm |
| Max bar diameter | Ø80 | mm |
| Max length | 600 | mm |
| Setups saved | 2–3 typical | note |
| Surface roughness | Ra 0.4 | µm |
Available Materials
- Stainless 303
- Stainless 17-4 PH
- Steel 4140
- Brass C360
- Titanium 6Al-4V
Typical Applications
- Hydraulic fittings with cross-holes
- Sensor bodies
- Valve spools
- Medical instrument parts
- Connector shells
Surface Finishes
- As-machined
- Passivate
- Anodise
- Nickel plating
- Polished
Industries Served
- Hydraulics & Pneumatics
- Medical
- Aerospace
- Automotive & EV
- Instrumentation
What drives the price of this part
Derived from the callouts on this page. Where a driver is not on the drawing, it is not on this list.
- Tolerance
- Diameter tolerance at ±0.005 mm is the tightest callout this family carries. Tightening a callout is a process decision, not a machining decision: below the standard ±0.005 mm the work moves to grinding or jig boring, and the price moves with it.
- Part size
- Max bar diameter at Ø80 mm decides which machine the part lands on and how many setups it needs. Size is the driver buyers most often leave out of a first enquiry, and it is the one that changes the quote fastest.
- Surface finish
- Surface roughness at Ra 0.4 µm. Every step below the ordinary as-machined Ra 1.6 µm adds a finishing pass; a callout on a face nobody touches is the most common over-specification we quote.
- Material
- The first material listed, Stainless Steel 303, rates 6/10 on our machinability scale at 228 HB. On this shop's scale a harder alloy means slower passes and more tool changes, and that is cycle time the quote has to carry.
- Order size
- Minimum order is 25 pieces, where setup and tooling are amortised across the batch and per-part cost settles around cycle time and material. Below that quantity the same part costs more per piece, not less.
See how cycle time is calculated in the machining time calculator and what else moves a price in the cost driver reference.
How these parts are inspected
Matched to the callouts above and the instruments actually on the floor.
- Coordinate measuring machine (Zeiss CONTURA G2, two machines, GR&R 8.4% on the critical feature)
- Dimensional report against the drawing, with a 100% check on critical features rather than a sample
- Certificate of conformance and the mill certificate with every shipment
- Surface roughness tester (Mitutoyo) against the Ra callout
- Bore gauges and an optical comparator for hole position and edge form
- First article inspection to AS9102, because this family carries an aerospace or automotive certificate
The full equipment list, with counts, is on the capability page; the inspection sequence is on quality and inspection.
Questions buyers ask
- What makes a part a good mill-turn candidate?
- Off-axis features that must relate to a turned diameter - cross-holes, flats, slots. If a second setup would need a fixture to hold that relationship, mill-turn is usually cheaper.
Related part families
Precision Turned Components
Turned parts with live tooling - flats, cross-holes and threads in one setup, ±0.005 mm.
5-Axis Machined Components
Complex 5-axis parts machined in one setup, holding true position on bores across five faces.
Swiss-Turned Parts
Small-diameter long parts turned on Swiss-type lathes, holding 0.005 mm without deflection.